Fixing device for a driving roller of an automatic screen printing machine



y 31, 1962 HISAKICHI ICHINOSE 3,046,879

FIXING DEVICE FOR A DRIVING ROLLER OF AN AUTOMATIC SCREEN PRINTINGMACHINE 3 Sheets-Sheet 1 Filed D80. 15. 1959 Hrsnmcnr ICHINOSE Bi l/M,

ATTORNEYS y 31, 1962 HISAKICHI ICHlNOSE 3,046,879

FIXING DEVICE FOR A DRIVING ROLLER OF AN AUTOMATIC SCREEN PRINTINGMACHINE 2 & E U m 5m N s 0 R N W 0 S T. a w] e I 1 mu m Filed Dec. 15,1959 July 31, 1 2 HISAKICHI ICHINOSE 3,046,879

FIXING DEVICE FOR A DRIVING ROLLER OF AN AUTOMATIC SCREEN PRINTINGMACHINE Filed Dec. 15, 1959 5 Sheets-Sheet 3 HISAKICHI IcHIlvosEINVENTOR.

Wilda/M ATTORA/EKS United States Patent 3 046,87 9 FIXING DEVICE FOR ADRIVING RGLLER OF AN AUTOMATIC SCREEN PRINTING MACHINE HisakichiIchinose, 57 Sanbancho, Koushien, Nishinomiya City, Hyogo Prefecture,Japan Filed Dec. 15, 1959, Ser. No. 859,608 Claims priority, applicationEapan May 23, 1959 4 Claims. (Cl. 101115) This invention relates tomeans for fixing a driving roller for an automatic screen printingmachine in'the correct position in the intervals between successiveadvancements thereof by the intermittent driving means for the machine.

It is an object of the present invention to provide means for correctlyfixing the driving roller of a screen printing machine in place in theintervals between the intermittent advancement thereof so that theprinting on the cloth driven by means of the driving roller can becarried out accurately. This is accomplished by locking the drivingroller in position when it stops, thus holding it in a fixed positionand preventing the slight deviations from the regular stopping positionwhich have heretofore been inevitable in such machines.

The invention is applicable to the usual type of screen printing machinefor printing on a length of cloth, the machine having a driving rollerpositioned near one end thereof and an idler roller near the other end,and having an endless belt extending between these rollers. Drivingmeans is connected to said driving roller to drive it intermittently.Along the upper run of the endless belt are a plurality of printingframes having printing squeegees, and means are provided for moving thescreens into contact with the cloth on the belt when the .belt isstopped. When the printing frames contact the cloth, the squeegees aremoved back and forth across the screen to spread printing paste throughthe pattern on the screen and onto the cloth.

In order to hold the belt, and consequently the cloth carried thereby inthe proper position when the belt has stopped moving, the presentinvention provides a gear on one end face of the driving roller.Adjacent the gear is a piston-cylinder mechanism having a member on thepiston in the form of a rack which will fit into the teeth on the gear.The piston-cylinder mechanism can be connected to a source of pressuremedium through an intermittently acting valve mechanism which isactuated in synchronism with the part of the printing machine whichintermittently drives the belt. Thus when the belt is stopped, thepiston-cylinder mechanism will be actuated so as to engage the rack withthe gear and thereby fix the driving roller in position when it hasstopped.

In the following description, this invention is more thoroughlyexplained with reference to the attached drawings in which,

FIG. 1 is a partial side elevation view of the automatic screen printingmachine with a multiple printing squeegee moving mechanism of thisinvention;

FIG. 2 is a side-view of the remaining part of the said automatic screenprinting machine, 'the figures to be joined at line T--T at the rightend of FIG. 1 and line T--T at the left end of FIG. 2;

FIG. 3 is theplan view of FIG. 1;

FIG. 4 is the plan view of FIG. 2, FIGS. 3 and 4 to be joined at line UUat the right end of FIG. 3 and line UU at the left end of FIG. 4;

3,046,879 Patented July 31, 1962 ice FIG. 8 is a vertical sectional viewof the rotary valve of FIG. 7;

FIG. 9 is a cross-sectional plan view of the rotary valve of FIG. 7rotated from the position shown in FIG. 7;

FIG. 10 is the vertical sectional view of the rotary valve of FIG. 9.

FIG. 11 is a perspective view of the rotary valve shown in FIGS. 7 to10; and

FIG. 12 is a perspective view of the rotary control member containedinside the said rotary valve.

As described above, this invention relates to a device for fixing thedriving roller of an automatic screen printing machine in a correctposition.

FIGS. 1 to 4 show the automatic screen printing machine equipped withthis invention. Frame 1 extends the entire length of this machine, atone end of which is a driving roller 2 at the other end is a followingroller 3.

Between these rollers is stretched an endless belt 4- in such a way thatthe said belt 4 may be intermittently advanced in the direction shown bythe arrow mark by intermittent revolutions of a driving roller 2. Inthis way, the following roller 3 is also revolved intermittently. Onthis endless belt 4, a plurality of printing frames 5 are arranged(FIGS. 2 and 4show 10 printing frames) and all of them are held by mainframe 6. Extending in the transverse direction of the said main frame 6are several guide rails 7 (FIGS. 2 and 4 show 6 guide rails), on whichsqueegee holders 8 are placed so as to be movable reciprocally in thetransverse direction of printing frames at the required time. Thesesqueegee holders can be joined to each other throughout the full lengthof the frame, or occasionally a few of them can be mounted to moveindependently of the others. From these squeegee holders, two or moresqueegees are hung in each printing frame so as to come in contact withscreens which are stretched across the bottom of each printing frame.Color paste is stored between the said squeegees to print cloth throughthe screen 56 when the squeegee slides on the screens. At the entry endof the frame 1, the feeding device 9 for cloth 12 to be printed isinstalled so that the cloth 12 is continuously fed from the entry to theexit, being agglutinated on the endless belt in accordance with theadvancesof endless belt. At the exit of the frame, the dryer 10 isinstalled for the after-treatment of printed cloth as shown in FIGS. 1and 3. The dryer 10 is equipped with a cloth discharge apparatus 11.

As seen in FIGS. 5 to 12, gear 17 is mounted on the side of drivingroller 2 and piston 18 slidable in cylinder 20 is positioned adjacent togear 17, the top of the said piston being machined to form a rack. Afeed port and a discharge port for the compressed liquid are arranged atthe upper and lower ends of cylinder 20, the said ports being coupledwith the one ends of pipes 13 and 14. The other end of each pipe isconnected with case 32 containing rotary valve 31. l

The rotary valve contained in case 32 is designed in such a way that thesaid rotary valve may either rotate continuously, the said valve 31being coupled directly with driving means which rotate continuously, orbe made to perform a repetitive motion by arranging an intermittentmotion generating means between the shaft of the rotary valve 31 and thecontinuously, rotating driving means. A pipe 12 for feeding thecompressed liquid to the rotary valve case 32 has one end connected withthe said case and the other end with a trochoid pump, a sinecurve gearpump or other such small rotary pump 26 of large capacity and highpressure at the other end. On the pipe 12 running between rotary valvecase 32 and 3 rotary pump 26, are positioned a receiver 24, a pressuregauge 25 and safety valve 23-. Safety valve 23 is not necessarilyrequired. The suction port of rotary pump 26 .by the driving mechanismfor the printing machine (as shown in FIG. 4, this driving mechanism 33is installed near the end of this printing machine for driving it),piston 18 is starting to rise and rotary valve 31 is rotating. While theprinting machine is being operated, motor 27 and rotary pump '26 alwaysrotate in a given direction at a constant velocity. Consequently, feedpipe 12 is filled with the compressed liquid, the said liquid beingdelivered through passage31a in valve 31 and through pipe 13' tocylinder 20 as indicated by the arrow. The compressed liquid then entersthe lower end of cylinder 20 so as to raise piston 18 in the directionshown by the arrow mark within a short period of time. This rise of thepiston causes the rack 19 to engage the teeth of gear 17 mounted on thedriving roller adjacent the said rack, thereby fixing driving roller 2exactly at the correct position, and at the,

same time preventing the inevitable slight deviation of the stoppingposition of the said roller from the correct position.

Since the lifting power of piston 18 is in proportion to the ratio ofsectional area of pipe 13 to the area of the bottom of piston 18, thesaid engagement may .be carried out with great force. Accordingly, whenthe tension of endless belt is not uniform throughout its full lengthdue to its uneven mounting on the circumferential surface of drivingroller 2 or the teeth of gear 17 on driving'roller 2 are slightlydisplaced from the position exactly opposite to rack 19 on piston 18,the tension of endless belt may be made uniform throughout its fulllength and the said teeth may be forced to the exact position for properengagement mentioned above. In this way, the most exact feed pitch forendless belt 4 may be satisfactorily maintained.

During the time rack 19 on piston 18 rises, the liquid above the upperside of the piston inside cylinder 20 is forced through the port in theupper part of cylinder 20 through pipe 14 to rotary valve case '32, andis returned through the passages 31b in rotary valve 31 and throughdischarge pipe to the compressed liquid reservoir because of theposition of the ports in rotary valve 31 which are turned to the properposition during the rising of piston 18. Consequently, the upward motionof piston 18 is performed as quickly as possible without any backpressure being generated in the liquid contained in the upper section ofcylinder 20. 7

Furthermore, the dwell times of the piston at both ends of its upwardstroke and downward stroke are sufiiciently long that the printing maysatisfactorily be carried out on endless belt 4 during the dwell time atthe end of the upward stroke, and the endless belt may be fully advancedduring the dwell time at the end of the downward stroke.

The dwell times described are about /2 as long as the period for onecomplete cycle of advance and rest of endless belt 4.

During the dwell periods at the ends of the upward and downward strokes,rotary pump 26 continues to feed liquid. Accordingly, the feed liquid istemporarily accumulated in receiver 24, compressing the air in the upperpart of the receiver. This prevents excess pressure from being exertedon piston 18 at the ends of the upward and downward strokes, becauseotherwise the cylinder might be damaged by the increase of the liquidpressure resulting from the constant feed of the liquid mentioned above.

Furthermore, safety valve 23 may be installed if desired for the purposeof furnishing a safety device to release the compressed liquid from thesystem through safety valve 23 and pipe 16 to compressed liquidreservoir 28.

After printing has been satisfactorily carried out on the endless belt 4which has been stopped, the compressed liquid coming from feed pipe 12is delivered in directions opposite to the arrow marks, namely, throughpipe 14 to the inside of cylinder 20 above piston 18 when rotary valve31 is moved to the position shown in FIG. 6. FIGS. 5 and 6 illustrate anembodiment in which rotary valve 31 performs an oscillating movementthrough an angle of FIG. 6 shows the rotary valve 31 turned 45 degreestothe right from the position in FIG. 5. The compressed liquid enteringthe section of the cylinder above the pis ton pushes the piston down,thereby disengaging rack 19 at the top of piston 18 from the teeth ofgear 17. At'

the same time, the liquid beneath the piston 18 is re turned throughpipe 13, rotary valve 31 and discharge pipe 15 to the liquid reservoir28. r

The functions of receiver 24 and safety valve 23 during the period oftime piston 18' is at the end of its downward stroke are quite similarto those at the end of its upward stroke as explained in the foregoingdescription. At the time when rack 19 is disengaged from the teeth .ofgear 17, gear 17, driving roller 2 and endless belt 4 are advanced onestep by other intermittent moving means .of this printing machine.

FIGS. 7 to 10 show an embodiment where the rotary valve does notoscillate, but rather rotates continuously;

FIGS. 9 and 10 show the position of rotary valve 31 when it has beenturned 180 degrees from the position shown in FIGS. 7 and 8. The rotaryvalve member is mounted on a shaft 29, and has a central web member 35by which it is secured to the shaft. Extending in opposite direc- Vtions from, the web member and parallel to the shaft 29 are cylindricalwalls 36a and 36b, each of which has ;a series of holes 37a and 37btherearound. These holes are in alignment with a single hole through thecasing 32 which gives access to the conduit 15. In the casing 32 arepassages 38 which open into the portion of the casing in which thecylindrical portion 36a is positioned, and with which an aperture 39a isaligned. The aperture 391: is aligned with the passage 38 which connectswith the pipe 14 in the position shown in FIGS. 7 and 8, whilein theposition shown in FIGS. 9 and 10, it is aligned with the passage 38communicating with pipe 13.

The holes 37b in the cylindrical portion 36b are alignable with a holein the casing 32 which leads to the pipe 12. The cylindrical portion 36balso has an aperture 39b therein, which in one position is in alignmentwith the passage 41 in the valve casing which communicates with pipe 13,(as shown in FIGS. 7 and 8), and in the other position is in alignmentwith the passage 41 communicating with pipe 14 (as shown in FIGS. 9 and10). The aperture 39b is positioned degrees around'the valve 31 from theaperture 39a.

It will be seen that, as the shaft 29 rotates to rotate thevalve 31, thepipe 14 will first be connected to the pipe 15, while the pipe 12 willbe connected to pipe 13, and when the valve has rotated 180 degrees, thepipe 12 will be connected to the pipe 14, and the pipe 13 will beconnected to the pipe 15.

Moreover, the cover of rotary valve case 32 can be removed when themachine is stopped, and the timing of v the rotary. valve may easily bcontrolled by readjusting the position of the rotary valve by looseningthe nut on' the end of the rotary valve shaft.

Since in the device of this invention, the piston is actuated by liquidpressure, as explained above, satisfactory control of the drivingroller, correction of its displacement and prevention of the error infeeding the belt may effectively be performed with the powerful pressureof the compressed liquid. Moreover, by arranging a receiver at anintermediate point in the pressure fluid system, the

capacity of the rotary pump may be kept at a minimum. Consequently, theelectric power consumption can be minimized.

Furthermore, the small capacity of the rotary pump has the eifect thatthe piston is operated smoothly without causing any percussion as aresult of its vertical reciprocation, because the encounter of the valveports with the feed and discharge ports at the times when the pistonstarts to move and stop during both the upward and downward strokes, isgradually accomplished.

It is thought that the invention and its advantages will be understoodfrom the foregoing description and it is apparent that various changesmay be made in the form, construction and arrangement of the partswithout departing from the spirit and scope of the invention orsacrificing its material advantages, the forms hereinbefore describedand illustrated in the drawings being merely preferred embodimentsthereof.

What is claimed is:

1. In a screen printing machine, the combination of a driving roller foran endless belt on which the material to be printed is carried throughthe machine, means for intermittently driving said roller, and means forfixing said roller in position in the intervals between successiveadvancements thereof by said intermittent driving means, said fixingmeans comprising a gear on one end of the roller, a piston adjacent thegear having a rack on the end thereof toward the gear and engageabl withthe gear, a cylinder in which said piston is slidable, a reservoir forpressure fluid, a pump connected to said reservoir for drawing pressurefluid therefrom, a rotary valve movable between at least two positions,and conduit means from opposite ends of said cylinder to said rotaryvalve and from said rotary valve to said pump and to said reservoir,said rotary valve having a rotatable valve member having passagestherein which in one position connect the conduit means from the pump tothe conduit means to one end of said cylinder and connect the conduitmeans from the other end of said cylinder to the conduit means to saidreservoir, and which in the other position connect the conduit meansfrom the pump to the conduit means to the other end of the cylinder, andconnect the conduit means from the one end of said cylinder to theconduit means to said reservoir, whereby rotation of the rotary valvecauses said piston to reciprocate and causes the teeth of the rack toengage the teeth of the gear at timed intervals. 1

2. The combination as claimed in claim 1 in which said valve oscillatesbetween two positions.

3. The combination as claimed in claim 1 in which said valve iscontinuously rotatable, and means for rotating said valve.

4, The combination as claimed in claim 1 in which said conduit meansfrom the pump to the rotary valve has a receiver connected thereto and asafety valve thereon, said safety valve having an overflow to saidreservoir.

References Cited in the file of this patent UNITED STATES PATENTS2,355,930 Thorne Aug. 15, 1944

